1. Field of the Invention
This invention relates to means for positively precluding searing of the firing pins in a Gatling type gun.
2. Prior Art
In U.S. Pat. No. 125,563, issued Apr. 9, 1872 to R. J. Gatling, there is shown the classic modern revolving battery gun. A stationary housing encloses and supports a rotor assembly which has a plurality of gun barrels and a like plurality of gun bolts. Each bolt has its own firing pin and mainspring. Each bolt is traversed longitudinally by a stationary elliptical cam track in the housing. As the bolt is traversed forwardly, its firing pin is captured to the rear by a stationary cam track in the housing, compressing its mainspring until the bolt and the barrel reach the firing position, at which position the stationary cam releases or sears the firing pin to impact the primer of the round.
R. E. Chiabrandy in U.S. Pat. No. 3,380,341, issued Apr. 30, 1968, shows a Gatling type gun having a single mainspring serving each of the plurality of gun bolts. A safing function is provided by a sector of the housing cam track which can be swung away from the bolts and which has a projection to block the mainspring.
R. G. Kirkpatrick et al in U.S. Pat. No. 3,611,871, issued Oct. 12, 1971, shows a Gatling type gun having a plurality of gun bolts and respective mainsprings. Each bolt is traversed longitudinally by a housing elliptical cam, and is rotated into lock by a cam in the aft end of the housing. A positive lock on the firing pin is released by rotating of the bolt into lock. A safing function is provided by shifting the aft cam to preclude rotation of the bolt.
R. M. Tan et al in U.S. Pat. No. 3,738,221, issued June 12, 1973, shows a Gatling type gun having a plurality of gun bolts and respective mainsprings. Each mainspring has a cam follower which engages and rides on a transverse segment of an annular cam to compress the mainspring until it rides off a sharp drop in the cam to actuate the firing pin. A safing element may be swung about an axis which is transverse to the gun longitudinal axis and substantially tangential to the cam into the gap defined by the drop to gradually lower the cam follower and decompress the mainspring to preclude actuating the firing pin.
In the GAU-8 gun as carried by the A10 aircraft, a cam somewhat similar to that shown by Tan is used. However, the safing element is pivoted about an axis which is parallel to the gun longitudinal axis.
In the cam system of the present GAU-8 gun, should the gun halt with a gun bolt having its cocking pin disposed in the gap defined by the drop in the cam, then the safing element cannot be swung fully into the gap because it is blocked by the cocking pin of the gun bolt. Force applied to the safing element merely tends to squash the cocking pin into the side of the gun bolt.